Floating roof and sealing means therefor



April 17, 1928. 1,666,525

' c. F. H. BOHNHARDT FLOATING ROOF AND SEALING MEANS THEREFOR Filed Au 20, 1925 2 $heets-=het l 62/02: ["71 BOH/V/IJEDT "Pa tented Apr. 17, 1928.

1 f UNITED STATES PATENT OFFICE.

CHARLES I. H- BOHNHARDT, OF LONG BEACH, CALIFORNIA, ASSIGNOR OF ONE-HALF TO JOSEPH R. BARIL, OF LONG BEACH, CALIFORNIA.

FLOATING ROOF AND SEALING MEANS THEREFOR.

Application filed August 20, 1925.

My present invention being referred to as a floating roof and sealing means therefor, it may be understood to be an object of this invention to provide tanks, such as oil or gas tanks, with roofs which are adapted to move up and down within a circular enclosing wall; and a preferred embodiment of my invention may comprise a substantially circular horizontal roof section terminating peripherally in a cylindrical element constituting an inner Wall of an annular pocket adapted to contain water or another liquid, the outer wall of this pocket being spaced but slightly from the outside wall of the tank, and said annular pocket being adapted to receive also a plurality of telescopically interfitting cylindrical bands respectively provided with interfitting terminal portions constitutin means for holding the same in their inten ed concentric and overlapping relationship during the rise and fall of said central roof section and substantially pre venting the entrance of air or the escape of the confined fiuid regardless of the elevation or depression of said central roof section.

To allow for escape and entrance of air as the tanks are filled and emptied, and allow for expansion and contraction of the contents with chan es in temperature, tanks currently used. in the storage of gasoline, or the like, are commonly left open to the air; but this results not only in the accumulation of explosive gaseous mixtures in the spaces above oil levels, but in extensive losses by evaporation; and it is an object of this invention substantially to avoid the risks and losses incidental to this described current construction.

It is an object of this invention to rovide an oil tank, or the like, with a mova le roof so supported as to avoid any large space for the accumulation of gases, and a preferred embodiment of my invention may'comprise a roof adapted to rest directly upon the top of a body of liquid, rising and falling with the expansion and contraction .or increase and diminution thereof.

It is a further object of my invention to provide a tank comprising an ordinary cy lindrical shell with a roof adapted to rise substantially to thetop thereof or to descend, and a preferred embodiment of this invention may comprise a tank havin vertical interior guides and a floating roo provided with a circumferential trough for a .tively provided with Serial No. 51,371.

sealing liquid and with rollers adjustably disposed therebelow, this trough housing telescopically interfitting sections respecsubsidiary liquid-seal troughs; and preferred embodiments of my invention may comprise a truss system external to the mentioned roof, and struts extending therefrom toward the lower edge of said circumferential trough, and optionally also supplemental supports adapted to aid in carrying the weight of the roof Whenever a tank is completely empty or is drained down to a low level.

Other objects of my invention may be best understood from the following description of an advantageous embodiment thereof, taken 1n connection with the appended claims and the accompanying drawings, in which Fig. 1 is a partial top plan view.

Fig. 2 may be regarded as a vertical halfsection, with parts broken away, taken substantially as indicatedby the line 22 of Fig. 1, and showin my floating roof as 00- cupying its elevated position.

Fig. 3'is a view comparable to the right hand portion of Fig. 2, but showing the roof as in a partially lowered position.

I Fig. 4 is a fragmentary horizontal section, taken substantially as indicated by the line 44 of Fig. 2.

Fig. 5 is a detail view showing an optional construction especially suitable for use in preventing. the sealing liquid from being blown out as a result of interior gas pressure.

Referring to the details of that specific embodiment of my invention shown in Figs.

1 to 4 inclusive, 11 may be the outer shell or main wall of a substantially circular tank designed for the storage of a combustible g5 being shown rigidly secured at its lower edge to the plate 19, and the last as rigidly secured at its upper edge, by means comprising .zthe main wall or outer shell 11.

A circular opening 36, provided with a tightly closable cover 37, may be located at or near the center of our floating roof; subsidiary legs 38 may be secured at any appropriate intervals therebelow, to support the root from the bottom 24 when the tank is empty; angle members 24', or their equivalent, may be used as required for reinforcement; and means such as struts 25, shown as extending bet-ween plate 12 and oppositely disposed channel el ments 26, secured to the plate 19 and carrying rollers 27, may contribute to the rigidity of the entire floating roof organization,-rollers 27 being preferably grooved, as at 28, to interfit wlth substantially vertical rails 29, which may be secured by. additional sectionstof channel bar 24 and may contribute to the rigidity of the tank, whether or not the bottom is slightly wider than the top, as shown. The wheels 27 may be adjustable by means such as nuts 30, on a threaded rod 31, projecting from a yoke 32.

The main peripheral trough 16 being normally kept filled with a sealing liquid, which may be water, and the respective top and bottom edges of the subsidiary sections 20, 23, -being oppositely rebent, as at 33 and 34, in such manner as to form subsidiary seals 35. (see Fig. 3) it will be obvious that my floating root' may rise and fall without loss of seal. Oil, or the like, may be delivered into the tank.by valved pipes (not shown) and as soon as the level of this introduced oil shall reach the plate 12, the cover 31 on a manhole 36 may be tightly closed; so that the entire roof must float up with the rise of the oil, no appreciable space being left for the accumulation of explosive ases. 4 g Even if the cover 37 is not tightly closed, the concavity provided by the plate 12 and the vertical elements 17 and 36, said vertical elements being shown as carried above the level of said plate, may be compared with the hull of a non-sinkable' boat, tending to rise with the oil level; and I may obtain substantially all of the advantages of my invention, as used for the storage of oil, even if I provide breather openings, of a known type, as at B and B; but when gases are to bestored in my tanks, it will be ob-- vious that no such openings are intended to be provided; and, whenever the interior ressures are such that the sealing liquid is liable to be disturbed by escaping gases or vapors, I may prefer to employ subsidiary sealing members of the types shown in Fig. 5 as comprising rebent rims 33' and 34',-the former having associated therewith an upstanding flange 35 of suflicient height to provide a pocket so deep that the sealing. liquid is in no danger of being cari ried above its upper ,edge by an outward rush of gas or vapor.

.Rain water fal ing on the roof of'a tank equipped and closed in the manner described can ordinarily do no harm, although itmay make up any deficiency in the sealing liquid,

and may even be enabled to make its way in any appropriate additional supports (not,

shown) being provided as required therefor. Although I have herein described a single complete embodiment of my invention, suggesting various alternative details, it should. be understood that various features of my invention may be independently employed; and also that numerous modifications might be devised by those skilled in the art,*w1thout the slightest departure from the spirit and 'scope of my invention, as the same is indicated lowing claims.

I claim as my invention:

1. A tank and roof construction comprising a main outer shell provided with guides therein; a roof vertically movable between said interior guides; and liquid seal means between said shell and said roof, said guides being engaged by rollers disposed below said liquid seal means.

2. A tank and roof construction comprising a shell adapted to contain a fluid; a roof adapted to overlie and float upon the fluid so contained; sealing means therebetween comprising a major trough secured to said roof and adapted to contain telescopically interfitting subsidiary shell elements, the outermost of said interfitting elements being above and in the folrigidly secured to said shell.

3. A tank and roof construction com rising a shell adapted to contain a flui a roof adapted to overlie and float upon the fluid so contained; sealing means therebe- I tween comprising a major trough secured to said roof and adapted to contain telescopi- 5. A tank roof comprising a substantially horizontal floating closure member adapted directly to overlie 2. contained liquid, a circumferential liquid seal trough extendin above and below the level of said roof and containing telescopicall interfitting subsidiary shell elementska apted to extend between .said trough and a main outer shell, the outermost of said interfitting elements being rigidly secured to said shell.

6. A tank and roof construction comprisin a main outer:shell rovided with guide rails therein; and a roof provided with rollers engaging said guide rails, said roof being provided wltha vertically expanding seal-' ing element including a. circumferential sealengaging said guide rai s, said roof being provided with a circumferential sealing trough, and said shell being provided with adownwardly extending expansible subsidiary interior shell element secured at its upper edge to said main outer shell.

In testimony whereof, I have hereunto set my hand at Los 'Angeles, California, this 1st day of August CHARLES H. BOHNHARDT. 

